tRecX - An environment for solving time-dependent Schrodinger-like problems

Scrinzi, Armin (2021): tRecX - An environment for solving time-dependent Schrodinger-like problems. In: Computer Physics Communications, Bd. 270, 108146

Abstract

tRecX is a C++ code for solving generalized inhomogeneous time-dependent Schrodinger-type equations id Psi/dt = H[t, Psi] +Phi in arbitrary dimensions and in a variety of coordinate systems. The operator H[t, 11] may have simple non-linearities, as in Gross-Pitaevskii and Hartree(-Fock) problems. Primary application of tRecX has been non-perturbative strong-field single and double photo-electron emission in atomic and molecular physics. The code is designed for large-scale ab initio calculations, for exploring models, and for advanced teaching in computational physics. Distinctive numerical methods are the time-dependent surface flux method for the computation of single and double emission spectra and exterior complex scaling for absorption. Wave functions and operators are handled by tree-structures with the systematic use of recursion on the coarse-grain level. Numerical, analytic, and grid-based discretizations can be combined and are treated on the same abstract level. Operators are specified in the input using a script language including symbolic algebra. User-friendly in-and output, error safety, and documentation are integrated by design. Program summary Program title: tRecX - time-dependent Recursive indeXing (tRecX=tSurff+irECS) CPC Library link to program files: https://doi .org /10 .17632 /zdjbnjxzrn .1 Developer's repository link: https://gitlab .physik.uni -muenchen .de /AG -Scrinzi /tRecX Code Ocean capsule: https://codeocean .com /capsule /5391166 Licensing provisions: GNU General Public License 2 Programming language: C++ Nature of problem: tRecX is a general solver for time-dependent Schrodinger-like problems, with applications mostly in strong field and attosecond physics. There are no technical restrictions on the spatial dimension of the problem with up to 6 spatial dimensions realized in the strong-field double ionization of Helium. A selection of coordinate systems is available and any Hamiltonian involving up to second derivatives and arbitrary up to three dimensional potentials can be defined on input by simple scripts. Solution method: The method of lines is used with spatial discretization by a flexible combination of one dimensional basis sets, DVR representations, discrete vectors, expansions into higher-dimensional eigenfunctions of user-defined operators and multi-center basis sets. Photo-emission spectra are calculated using the time-dependent surface flux method (tSurff) in combination with infinite range exterior complex scaling (irECS) for absorption. The code is object oriented and makes extensive use of tree-structures and recursive algorithms. Parallelization is by MPI. Code design and performance allow use in production as well as for graduate level training. (C) 2021 Elsevier B.V. All rights reserved.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0010-4655
• Sprache: Englisch